Intraventricular solitary fibrous tumor: an unusual tumor with radiological, ultrastructural, and immunohistochemical evaluation: case report.

Objective And Importance: Intracranial solitary fibrous tumors have been described previously, but intraventricular solitary fibrous tumors are extremely rare. We present what is, to our knowledge, the first reported case of solitary fibrous tumor in the third ventricle.

Clinical Presentation: A 63-year-old man presented with weakness of his lower extremities and headaches. Computed tomography and magnetic resonance imaging of the brain revealed an enhancing mass in the posterior part of the third ventricle.

Intervention: The tumor originated from the wall of the left internal cerebral vein and extended to the posterior part of the third ventricle. Nearly total excision was performed via an infratentorial-supracerebellar approach.

Conclusion: The differential diagnosis of intracranial solitary fibrous tumors includes fibroblastic meningioma, meningeal hemangiopericytoma, neurofibroma, and schwannoma. The differential diagnosis in the present case was greatly helped by the immunohistochemical and ultrastructural findings, along with a disease-free 3.5-year follow-up. These findings are presented with reference to previous reports.